1. Field of the Invention
The present invention relates to a method for making a barrel for plate member fastener and installing the barrel in a first metal plate member for enabling the plate member fastener to affix the first metal plate member to a second metal plate member. The invention also relates to a plate member fastener for joining two metal plate members of which the barrel that is to be bonded to the first metal plate member by a reflow soldering process has a solder mask at the bottom side to prevent solder paste bridging and wicking under components.
2. Description of the Related Art
When fastening plate members together, a positioning screw formed of a knob, a ring and a screw nail is usually used. During installation, the screw nail and the ring are secured to the first plate member, and then the knob is rotated to drive the screw nail into the second plate member, and then a hand tool is used to fasten tight the screw nail, affixing the first and second plate members together. This plate member joining method can be used in a machine tool to join plate members together.
The power drive or speed-adjustment unit of a machine tool is provided inside the housing. To facilitate repair of the machine tool or adjustment of the output speed of the machine tool, a detachable plate member is usually provided at the housing of the power drive or speed-adjustment unit. Screw bolts are commonly used to fasten the movable plate member to the housing. When unfastening screw bolts to dismount a movable plate member from the housing, the associating lock nuts may fall from the screw bolts.
There is known a plate member fastener comprised of a cap, a screw, a spring member and a locating base for joining two metal plate members together. After fixation of the locating base of the plate member fastener to a through hole on a first plate member, the screw is threaded into a screw hole on a second plate member to secure the first plate member and the second plate member together. Because the locating base of the plate member fastener is kept secured to the first plate member after removal of the first plate member from the second plate member, the plate member fastener will not be missed by accident. During installation of the plate member fastener, an automatic installation machine is used to pick up the locating base and then to insert the locating base into the mounting through hole of the first plate member. Thereafter, the locating base is bonded to the first plate member with a solder paste by means of a reflow soldering process, and then the spring member is sleeved onto the screw inside the cap and supported between the cap and locating base at the first plate member after insertion of the screw into the locating base and fastening of the screw to the second plate member.
The locating base is a hollow member made of stainless steel or any other metal material processed through a surface treatment (electroplating or chemical plating). The surface characteristic of the locating base does not facilitate the performance of soldering, therefore a solder paste must be used and applied to the front side of the locating base and/or the top wall of the first plate member when performing a reflow soldering to bond the locating base to the first metal plate member. During reflow soldering, the liquefied solder paste may permeate through gaps in between the locating base and the first metal plate member, resulting in solder paste bridging and wicking under components. When this problem happens, the solder paste may block the bottom opening side of the locating base, complicating further mounting of the screw of the plate member fastener and weakening the bonding strength between the locating base and the first metal plate member
Accordingly, there is a need for plate member fastener that overcomes, alleviates, and/or mitigates one or more of the aforementioned and other deleterious effects of the prior art plate member fastener.